In the proposed study, we will integrate a modular array of miniaturized air monitors for use as personal and residential monitors for future epidemiological studies that will test hypotheses on asthma development and asthma exacerbation. Our overall approach is to develop and test (a) a real-time monitor that can serve as a platform to record its own data and data from other monitors to establish spatial and temporal variations of potential acute asthma stressors and (b) a monitor that can collect either spatially- or time- resolved, integrated samples that can be archived for subsequent analysis in the laboratory. Time scales for battery-powered deployments of both the real-time monitors and the integrated sampler could range from 24 hours to a month in duration depending on the study design. Three aims form our proposal. Aim 1) Integrate a modular array of miniaturized air monitors for use as residential and personal monitors. The three monitors that make up our modular array currently exist in various stages of development: a completed monitor that is not fully validated (the Multi-day microAeth(r)), a prototype that will be further miniaturized while expanding functionality (the Archive Monitor) and an off the shelf inexpensive smart phone enabled monitor for airborne particulates (The Airbeam from Aircasting.org). Tri-axial accelerometer and GPS chips are integrated into our personal monitors allowing determinations of location, wearing compliance and activity related parameters. The multi-day microAeth monitor, measures optically absorbant components of particulate matter including black carbon and environmental wood smoke. Bluetooth, WiFi and/or serial connections will allow all sensor data to be logged on the multi-day microAeth(r) to simplify integration and allow all sensor data (personal and residential) to be sent to the study team on a daily basis. We include the Airbeam to show capacity of our platform for integrating data streams from third-party monitors and to show capacity for integrating our sensor data into a pre-existing smart phone app. Aim 2) Refine or develop sensitive analytical methods for a wide suite of asthma-related exposure measurements for archive, integrated samples of PM10, PM2.5 and semi-volatile compounds. The initial suite of measurements to be validated for the archive samples includes airborne allergens (mouse, dust mite and cockroach), PCR based microbial assays, semi-volatile and particle-associated non-volatile PAHs, black carbon, particulate-bound elements, and gravimetric determinations of PM10 and PM2.5 filters. Aim 3) Carry out laboratory and field tests iteratively to identify challenges in using the devices, improve protocols, and determine reproducibility and accuracy of collected data. Field tests will include comparisons to other monitors and feasibility pilots with a cohort of asthmatic children for testing the modular array o air monitors. Feasibility outcomes of interest include data completeness, wearing compliance, and demonstration of the ability to transfer data to future data coordinating centers.